System and method for conditioning a power supply transmission for supply to a load circuit

ABSTRACT

A system and method for conditioning an alternating current (“AC”) power transmission for supply to a load circuit. In one aspect, the invention is a system comprising: a power conditioning circuit comprising a voltage surge protector for eliminating voltage spikes in the AC power transmission, an inrush current suppressor for limiting the current of the AC power transmission, a filter for reducing electromagnetic interference and radio frequency interference of the AC power transmission, and a voltage sensing circuit for monitoring a voltage level of the AC power transmission; means for electrically coupling the power conditioning circuit to a source of AC power; outlet means for electrically coupling the power conditioning circuit to a load circuit; wherein the voltage sensing circuit monitors the AC power transmission in a rectified un-smoothed state after the AC power transmission has passed through the filter; and wherein upon the voltage sensing circuit detecting that the voltage level of the AC power transmission exceeds a predetermined upper limit, the AC power transmission is prohibited from reaching the outlet means.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 11/293,669, now allowed, filed Dec. 2, 2005, the entirety ofwhich is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to the field of systems andmethods for protecting electrical loads from transient surges in asource of alternating current (“AC”) power. More specifically, thepresent invention relates to systems and methods for protectingelectrical loads from transient surges in a source of AC power thatremoves adverse characteristics that may be present in the powertransmission and provides an automatic disconnect upon detecting anovervoltage condition. Even more particularly, the present inventionrelates to systems and methods that provide voltage surge protection,in-rush current suppression, and and/or overvoltage detection anddisconnect to an AC power transmission.

BACKGROUND OF THE INVENTION

The prior art is replete with different types of devices and circuitsthat filter out undesired electrical characteristics from an incomingsource of electricity. In the United States of America, most every homeand business is supplied with power from a utility company. Typically,the power supplied from the utility company passes through a transformerand is supplied to a building with an alternating current of 120 voltsand a nominal frequency of 60 Hz. Although the power at the utilitycompany is generated at these voltages and frequency values, the actualpower received at a particular home or business can vary widelydepending upon both how the power is transmitted and how the power isused.

Power transmission lines emanating from utility companies are commonlyexposed to the elements as they travel from the utility company to ahome or business. As such, the power transmission lines are subject tolightning strikes, interference from sun flares, storm damage and thelike. All of these occurrences can create abnormalities in thecharacteristics of the power being transmitted. For example, a lightningstrike in a power transmission line can create a large voltage spike inthe power being transmitted. If this voltage spike is received by a homeor business, the voltage spike can cause catastrophic damage to anyelectronic load/equipment that receives it. Alternatively, power call bedisrupted if the spike causes a circuit breaker to trip.

Similarly, power transmission lines can receive electromagneticinterference (EMI) and/or radio frequency interference (RFI) fromnatural and manmade sources. The resulting EMI/RFI signals cause noisein the characteristics of the power transmission that can disruptsensitive electronic circuits that receive such power transmissions.

Power transmissions with undesirable characteristics can also be createdby the way power is used in a home or business. Many electronic devicesdraw a higher current when they are first turned on. This is because thecircuits in the electronic device/load are cold and the capacitors inthe circuits are not charged. However, soon after the circuit ispowered, the current drawn by that circuit can decrease dramatically. Asa result, when an electronic device is first turned on, there is aninrush of current, thereby causing a current spike. If multipleelectrical devices are all turned on at once, the inrush current spikecan be quite large and either cause a circuit breaker to trip or causedamage to the electronic components of those devices that experience thecurrent spike.

Additional undesirable characteristics experienced in power transmissionare that of overvoltage and/or undervoltage conditions. An overvoltagecondition is a hazardous condition that exists when the voltage of theincoming power is raised over a safe operating upper limit. Similarly,an undervoltage condition is a hazardous condition that exists when thevoltage of the incoming power is lowered below a safe operating lowerlimit. Depending on the duration, the under/overvoltage event can bepermanent or last for a substantial period of time. Because of theprolonged nature of an under/overvoltage condition, circuitry designedto merely protect against transient surges is inadequate.

In the prior art, there are many different devices that are used toeliminate adverse characteristics from a power supply. However, many ofthese devices are designed to filter out only one type of adversecharacteristic. For example, there are many types of commerciallyavailable surge protector items that can eliminate voltage spikes causedby lightning. Such prior art surge protectors are exemplified U.S. Pat.No. 4,870,534 to Harford (“the '534 Patent”), entitled Power Line SurgeProtector, the entirety of which is incorporated herein by reference.However, such prior art surge protection devices do not protect fromEMI/RFI signal interference, incidents of inrush current, or theoccurrence of under/over voltage conditions.

Similarly, devices exist in the prior art record that are designed tofilter EMI/RFI signal interference from power supplies. Such prior artfilters are exemplified by U.S. Pat. No. 5,530,396 to Vlatkovic,entitled EMI Input Filter Power Factor Correction Circuits, the entiretyof which is incorporated herein by reference. However, such prior artdevices do not protect against voltage surges, inrush current surges, orthe occurrence of under/over voltage conditions.

Moreover, devices exist in the prior art that are designed to eliminateinrush current surges. Such prior art devices are exemplified by U.S.Pat. No. 4,573,113 to Bauman, entitled Surge Protection System For A D-CPower Supply During Power-up, and U.S. Pat. No. 5,930,130 to Katyl,entitled Inrush Protection Circuit, the entirety of which isincorporated herein by reference. However, such prior art devices do notprotect against EMI/RFI signal interference, voltage surges, or theoccurrence of under/over voltage conditions.

To date, the most complete system and method for conditioning powerreceived from an AC power supply source and supplying the conditioned ACpower to the electronic load/equipment is disclosed in U.S. Pat. No.6,744,613 to McCook et al. (“the '613 Patent”), entitled System andMethod for Filtering Multiple Characteristics from a Power SupplySource, the entirety of which is hereby incorporated by reference in itsentirety. While the device disclosed in the '613 Patent providescombined protection against EMI/FRI interference, inrush currents, andtransient voltage surges, it does not provide adequate protectionagainst overvoltage and/or undervoltage power conditions.

Finally, while circuits do exists that generally provide protectionagainst over/undervoltage conditions, these circuits are limited toprotecting components in direct current (“DC”) circuitry. Such circuitsare not easily conformable to devices that receive, condition, and passalong AC power. Thus, the need still exists for a system and method forconditioning power from AC power supply source that can also provideprotection from over/undervoltage conditions.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a systemand method for conditioning AC power.

Another object of the present invention is to provide a system andmethod for conditioning AC power that can remove multiple adversecharacteristics from the AC power.

Yet another object of the present invention is to provide a system andmethod for conditioning AC power that can provide effective protectionto a load circuit from an overvoltage and/or an undervoltage condition.

Still another object of the present invention is to provide a system andmethod for conditioning AC power that can detect an overvoltage and/oran undervoltage condition and prohibit the AC power supply to the loadcircuit for the duration the overvoltage and/or an undervoltagecondition.

A further object of the present invention is to provide a system andmethod for conditioning AC power that can detect an overvoltage and/oran undervoltage condition, automatically disconnect the load circuitfrom the AC power supply source upon detection of the overvoltage and/oran undervoltage condition, and automatically reconnect the load circuitto the AC power supply source upon detecting that the overvoltage and/oran undervoltage condition has ended.

A still further object of the present invention is to provide a systemand method for conditioning AC power that can provide effectiveprotection to a load circuit from transient surges, inrush currents,and/or overvoltage conditions.

Another object of the present invention is to provide a system andmethod for conditioning AC power that can provide effective protectionto a load circuit from transient surges, inrush currents, EMI/RFIinterference, and/or overvoltage conditions. These and other objects aremet by the present invention, which in one aspect is a system forconditioning an incoming alternating current (“AC”) power transmissionfor supply to a load circuit. The inventive system comprises a powerconditioning circuit, means for electrically coupling the powerconditioning circuit to a source of AC power, and outlet means forelectrically coupling the power conditioning circuit to a load circuit.The power conditioning circuit comprises a voltage surge protector, aninrush current suppressor, and a voltage sensing circuit.

The voltage surge protector eliminates voltage spikes in the AC powertransmission. The inrush current suppressor limits the currentassociated with the AC power transmission. The overvoltage sensingcircuit monitors the voltage level of the AC power transmission. Whenthe voltage sensing circuit detects that the voltage level of the ACpower transmission exceeds a predetermined upper limit, the AC powertransmission is prohibited from reaching the outlet means. Thus, thecircuit load is automatically protected from the overvoltage condition.

In one preferred embodiment, the inventive system can also be designedto protect the load circuit from undervoltage conditions. In thisembodiment, the voltage sensing circuit is adapted to generate andtransmit an undervoltage signal to the controller when the voltage levelof the AC power transmission drops below a predetermined lower limit.Upon receiving the undervoltage signal from the voltage sensing circuit,the controller transmits a disconnect signal to the one or moreswitches, thereby manipulating the switches so as to prohibit the ACpower transmission from reaching the outlet means.

It is further preferred, in one embodiment, that the voltage sensingcircuit continue to monitor the voltage level of the AC powertransmission after the voltage level of the AC power is determined toexceed the predetermined upper limit or be below the lower limit.Thereafter, upon the voltage sensing circuit detecting that the voltagelevel of the AC power transmission returns to a value between thepredetermined upper limit and the predetermined lower limit, the ACpower transmission is automatically restored to the outlet means.

The AC power transmission can be prohibited from reaching the outletmeans thorough the control of one or more switches. In such anembodiment, a controller is preferably operably coupled to the voltagesensing circuit and the one or more switches. The voltage sensingcircuit generates and transmits an overvoltage signal to the controllerupon detecting that the voltage level of the AC power transmissionexceeds a predetermined upper limit. Upon receiving the overvoltagesignal from the voltage sensing circuit, the controller transmits adisconnect signal to the one or more switches, thereby manipulating theswitches so as to prohibit the AC power transmission from reaching theoutlet means.

In one embodiment, the relay switches within the inrush currentsuppressor call also be used to perform the disconnect function(s). Byutilizing the relay switches of the inrush current suppressor to alsoperform the disconnect function(s), the overall cost and complexity ofthe circuit is reduced.

In other embodiments, the system can further comprise: (1) a converterfor creating direct current (“DC”) power from the AC power transmission,the converter operably coupled to the controller for supplying DC powerto the controller; (2) a remote activation unit coupled to thecontroller; (3) a filter for reducing electromagnetic interference andradio frequency interference of the AC power transmission.; and/or (4)means for coupling the power conditioning circuit to a network, therebyfacilitating monitoring and/or control of the power conditioning circuitfrom a remote location.

As will be understood by those skilled in the art, the order in whichthe components of the above system are coupled to one another is notlimiting of the present invention call be varied as desired. However, inone preferred embodiment, the voltage surge protector is coupleddirectly to the means for electrically coupling the power conditioningcircuit to a source of AC power, thereby producing a surge protected ACpower transmission. The EMI/RFI filter is located after the voltagesurge protector, thereby receiving the surge protected AC powertransmission and outputting a filtered AC power transmission. Thefiltered AC power transmission is received by the inrush suppressor andconverted into a conditioned AC power transmission. The voltage sensingcircuit can be coupled to the EMI/RFI filter and the controller. Thecontroller is then coupled to the inrush current suppressor.

In another aspect, the invention can be a system for conditioning anincoming AC power transmission for supply to a load circuit, the systemcomprising: a voltage surge protector for eliminating voltage spikes inthe incoming AC power transmission, thereby producing a surge protectedAC power transmission; an inrush current suppressor that receives thesurge protected AC power transmission and limits the current associatedwith the surge protected AC power transmission, thereby producing aconditioned AC power transmission; an voltage sensing circuit thatreceives the surge protected AC power transmission and monitors avoltage level of the surge protected AC power transmission, the voltagesensing circuit adapted to generate and transmit an overvoltage signalwhen the voltage level of the surge protected AC power transmission isdetermined to exceed a predetermined threshold; and a controlleroperably coupled to the voltage sensing circuit (mid the inrush currentsuppressor, wherein upon receiving the overvoltage signal from thevoltage sensing circuit, the controller transmits a disconnect signal toone or more switches, thereby prohibiting the production of theconditioned AC power transmission.

In yet another aspect, the invention can be a system for conditioning anAC power transmission for supply to a load circuit, the systemcomprising: a power conditioning circuit comprising a voltage surgeprotector for eliminating voltage spikes in the AC power transmission,an inrush current suppressor for limiting the current of the AC powertransmission, a voltage sensing circuit for monitoring a voltage levelof the AC power transmission, one or more switches, and a controlleroperably coupled to the voltage sensing circuit and the one or moreswitches; means for electrically coupling the power conditioning circuitto a source of AC power; outlet means for electrically coupling thepower conditioning circuit to a load circuit; and the voltage sensingcircuit generating and transmitting an overvoltage signal to thecontroller when the voltage level of the AC power transmission exceeds apredetermined upper limit; and wherein upon receiving the overvoltagesignal from the voltage sensing circuit, the controller transmits adisconnect signal to the one or more switches, thereby prohibiting theAC power transmission from reaching the outlet means.

In still another aspect, the invention can be a system for conditioningan AC power transmission for supply to a load circuit, the systemcomprising: a power conditioning circuit comprising a voltage surgeprotector for eliminating voltage spikes in the AC power transmissionand an inrush current suppressor for limiting the current of the ACpower transmission; means for coupling the power conditioning circuit toa network thereby facilitating monitoring and/or control of the powerconditioning circuit from a remote location; means for electricallycoupling the power conditioning circuit to a source of AC power; andoutlet means for electrically coupling the power conditioning circuit toa load circuit.

In a further aspect, the invention can be a system for conditioning anAC power transmission for supply to a load circuit, the systemcomprising: a power conditioning circuit comprising a voltage surgeprotector for eliminating voltage spikes in the AC power transmissionand a voltage sensing circuit for monitoring a voltage level of the ACpower transmission; means for coupling the power conditioning circuit toa network thereby facilitating monitoring and/or control of the powerconditioning circuit from a remote location; means for electricallycoupling the power conditioning circuit to a source of AC power; outletmeans for electrically coupling the power conditioning circuit to a loadcircuit; and wherein the voltage sensing circuit is adapted so that upondetecting that the voltage level of the AC power transmission exceeds apredetermined upper limit, the AC power transmission is prohibited fromreaching the outlet means.

Any of the inventive systems can be modified to include any one, or anycombination, of the additional electrical components discussed in detailabove and described in the following specification.

In a still further aspect, the invention can be a method of conditioningan AC power transmission for supply to a load circuit, the systemcomprising: a) receiving an unconditioned AC power transmission from anAC power supply source; b) eliminating voltage spikes in the AC powertransmission and limiting the current of the AC power transmission,thereby creating a conditioned AC power transmission; c) transmittingthe conditioned AC power transmission to the load circuit; d) measuringa voltage level of the unconditioned AC power transmission or theconditioned AC power transmission; and e) disconnecting the transmissionof the conditioned AC power transmission to the load circuit upondetecting that the voltage level exceeds a predetermined upper limit.

In an even further aspect, the invention can be a system forconditioning an alternating current (“AC”) power transmission for supplyto a load circuit, the system comprising: a power conditioning circuitcomprising a voltage surge protector for eliminating voltage spikes inthe AC power transmission, an inrush current suppressor for limiting thecurrent of the AC power transmission, a filter for reducingelectromagnetic interference and radio frequency interference of the ACpower transmission, and a voltage sensing circuit for monitoring avoltage level of the AC power transmission; mean s for electricallycoupling the power conditioning circuit to a source of AC power; outletmeans for electrically coupling the power conditioning circuit to a loadcircuit; wherein the voltage sensing circuit monitors the AC powertransmission in a rectified un-smoothed state after the AC powertransmission has passed through the filter; and wherein upon the voltagesensing circuit detecting that the voltage level of the AC powertransmission exceeds a predetermined upper limit, the AC powertransmission is prohibited from reaching the outlet means.

In a yet further aspect, the invention can be a system for conditioningan alternating current (“AC”) power transmission for supply to a loadcircuit, the system comprising: a power conditioning circuit comprisinga voltage surge protector for eliminating voltage spikes in the AC powertransmission, an inrush current suppressor for limiting the current ofthe AC power transmission, and a voltage sensing circuit for monitoringa voltage level of the AC power transmission; means for electricallycoupling the power conditioning circuit to a source of AC power; outletmeans for electrically coupling the power conditioning circuit to a loadcircuit; wherein upon the voltage sensing circuit detecting that thevoltage level of the AC power transmission exceeds a predetermined upperlimit, the AC power transmission is prohibited from reaching the outletmeans within at least one half cycle of the AC power transmission; andwherein upon the voltage sensing circuit detecting that the voltagelevel of the AC power transmission drops below a predetermined lowerlimit, the AC power transmission is prohibited from reaching the outletmeans the outlet means only after a delay period has expired and thevoltage level of the AC power transmission is still below thepredetermined lower limit.

In a further aspect, the invention can be a system for conditioning analternating current (“AC”) power transmission for supply to a loadcircuit, the system comprising: a power conditioning circuit comprisinga voltage surge protector for eliminating voltage spikes in the AC powertransmission, an inrush current suppressor for limiting the current ofthe AC power transmission, a voltage sensing circuit for monitoring avoltage level of the AC power transmission, the inrush currentsuppressor having one or more relay switches, and a controller operablycoupled to the voltage sensing circuit and the one or more relayswitches; means for electrically coupling the power conditioning circuitto a source of AC power; outlet means for electrically coupling thepower conditioning circuit to a load circuit; the voltage sensingcircuit generating and transmitting an overvoltage signal to thecontroller when the voltage level of the AC power transmission exceeds apredetermined upper limit; wherein upon receiving the overvoltage signalfrom the voltage sensing circuit, the controller transmits a disconnectsignal to the one or more relay switches of the inrush currentsuppressor, thereby prohibiting the AC power transmission from reachingthe outlet means, and wherein during an inrush current condition, theone or more switches limit the current of the AC power transmission thatreaches the outlet means without disconnecting the AC power transmissionfrom reaching the outlet means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a power conditioning system according to oneembodiment of the present invention coupled to an alternating currentpower source and a piece of equipment.

FIG. 2 is a schematic of an exemplary EMI/RFI filter for use in thepower conditioning system of FIG. I according to one embodiment of thepresent invention.

FIG. 3 is a schematic of an exemplary power supply/converter circuit foruse in the power conditioning system of FIG. 1 according to oneembodiment of the present invention.

FIG. 4 is a schematic of an exemplary under/over voltage sensing circuitfor use in the power conditioning system of FIG. I according to oneembodiment of the present invention.

FIG. 5 is a schematic of an exemplary timing and control circuit for usein the power conditioning system of FIG. I according to one embodimentof the present invention.

FIG. 6 is a schematic of an exemplary inrush suppression and voltagedisconnect relay circuit for use in the power conditioning system ofFIG. I according to one embodiment of the present invention.

FIG. 7 is a schematic of a power conditioning system according to asecond embodiment of the present invention coupled to an alternatingcurrent power source and a piece of equipment, wherein the powerconditioning system comprises network control capabilities.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 discloses a power conditioning system 100 according to oneembodiment of the present invention. While the power conditioning system100 can be incorporated directly into the internal circuitry and/orhousing of many different types of electronic equipment, the powerconditioning system 100 is particularly well suited for use as aself-contained unit. In this manner, the present invention powerconditioning system 100 will comprise a separate housing that willcontain the circuitry described in FIGS. 1-7. As such, the powerconditioning system 100 can be used to condition incoming AC electricalpower and any separate electronic device/load circuit call then beconnected to the power conditioning system 100 to receive theconditioned power. Accordingly, in the exemplary embodiment of thepresent invention, the power conditioning system 100 is shown as aself-contained unit that is separate from the electronic equipment thatreceives electrical power through the power conditioning system.

The power conditioning system 100 is shown coupled to a source of ACpower 10 via a plug 12 at one end and to a piece of electrical equipment90 via an output port 13 at the other end. In one embodiment, the plug12 extends from the housing of the power conditioning system 100 and issoldered, or otherwise electrically coupled, to the power conditioningcircuitry located within the housing. In an alternative embodiment, apower jack/port can be provided in the housing for operably receivingand electrically coupling to a connector at an end of the plug 12. Thepower jack/port is in turn directly coupled to the power conditioningcircuitry located within the housing.

The source of AC power 10 can be a standard 120 volt outlet/receptaclein one's home or business, which in turn is operably coupled to utilitypower lines and receives AC power from the local utility company.Unconditioned AC power 11 is supplied to the power conditioning system100 via the plug 12. Upon receiving the unconditioned AC power 11, apower conditioning circuit within the housing of the power conditioningsystem 100 removes adverse characteristics that may be present in theincoming AC power transmission, monitors the voltage level of the ACpower transmission, and presents a conditioned AC power transmission tothe output port 13. In the illustrated embodiment, the output port 13 isa single receptacle that supplies filtered power to a single piece ofelectrical equipment 90 that is plugged into the power conditioningsystem 100.

Of course, the invention is not so limited. For example, a plurality ofreceptacles call be provided in the housing of so that multiple piecesof electrical equipment can be electrically coupled and protectedsimultaneously by a single power conditioning system 100. Moreover, inan alternative embodiment, the output port 13 can be the circuit breakerbox of a building, thereby providing conditioned AC power to everyreceptacle in the building.

Importantly, the power conditioning system 100 comprises a powerconditioning circuit comprising a voltage surge protector 20, an EMI/RFIfilter 30, an over/undervoltage sensing circuit 40, a low volt DC powersupply 50, a control circuit 60, a remote activation unit 70, and aninrush current suppressor 80. These components are electricallyconnected as shown in FIG. 1, wherein the electrical connections anddirection of electrical flow are indicated by the arrows. The internalelements and functions of each component of the power conditioningcircuit are described below in detail with respect to FIGS. 2-6.However, a high level description of the power conditioning circuit andits functioning is useful at this time.

Referring still to FIG. 1, the plug 12 is electrically connected to thevoltage surge protector 20. Thus, as the plug 12 receives anunconditioned AC power transmission 11 from the AC power source 10, thisunconditioned AC power transmission 11 is first received by the voltagesurge protector 20. The voltage surge protector circuit 24 eliminatestransient voltage spikes in the incoming unconditioned AC powertransmission 11 that may be caused by lightning strikes, shortedtransformers or the like, and outputs a surge protected AC powertransmission. In the prior art, there exist many different types ofvoltage surge protector circuits that can eliminate voltage spikes. Manyof these prior art circuits can be adapted for use in the presentinvention. However, the surge protector circuitry found in U.S. Pat. No.4,870,528 to Harford, entitled Power Line Surge Protector isparticularly advantageous and is preferred in the exemplary embodimentof the invention. Accordingly, the disclosure of U.S. Pat. No. 4,870,528to Harford is hereby incorporated into this specification by reference.

The output leads of the voltage surge protector 20 are electricallycoupled to the EMI/RFI filter 30. As a result, the surge protected ACpower transmission outputted by the voltage surge protector 20 isreceived by the EMI/RFI filter 26. Due to the presence of the voltagesurge protector 24, any transient voltage spikes in the received powersignal have been removed. However, EMI and/or RFI signal noise can stillbe present in the incoming surge protected AC power transmission. TheEMI/RFI filter 30 reduces the noise present in the surge protected ACpower transmission that call be categorized as either electromagneticinterference or radio frequency interference, thereby outputting afiltered AC power transmission. In the prior art, there exist many typesof EMI/RFI filters. Many of these prior art filters can be adapted foruse as part of the present invention power condition system 100.However, a specific EMI/RFI filter 30 is preferred in the exemplaryembodiment. This circuit will later be described with reference to FIG.2.

The output leads of the EMI/RFI filter 30 are coupled to the inrushcurrent suppressor 80. As a result, the filtered AC power transmissionis then transmitted to the inrush current suppressor 80 for furtherconditioning as will be discussed below. The inrush current suppressor80 acts as the third power conditioning component of the presentinvention, limiting the current of the filtered AC power transmissionand outputting a conditioned AC power transmission to the output port13. While one inrush current suppressor is illustrated, it is possibleto utilize a plurality of the inrush current suppressors 80 if desired.For example, multiple inrush current suppressors can be arranged in acascading array. As such, each of inrush current suppressors will beactivated after the previous inrush current suppressor has finishedpowering up. In this manner, separated groupings of electronic equipmentcan be kept on the same circuit without surpassing the amperage ratingfor that circuit when the various groupings of equipment are firstturned on.

The EMI/RFI filter 50 is also operably coupled to the low volt DC powersupply 50 and the under/overvoltage sensing circuit 40. Theunder/overvoltage sensing circuit 40 continuously monitors the voltagelevel of the filtered AC power transmission that exits the EMI/RFIfilter 30. Upon the under/overvoltage sensing circuit 40 detecting thatthe voltage level of the filtered AC power transmission either (1)exceeds a predetermined upper limit or (2) falls below a predeterminedlower limit, the under/overvoltage sensing circuit 40 will generate andtransmit a fault signal to the control circuit 60. In the event of anovervoltage condition, the under/overvoltage sensing circuit 40 willgenerate and transmit an overvoltage signal to the control circuit 60.Similarly, in the event of an undervoltage condition, theunder/overvoltage sensing circuit 40 will generate and transmit anundervoltage signal to the control circuit 60.

Upon receiving the fault signal from the under/overvoltage sensingcircuit 40, the control circuit 60 will send a disconnect signal to theinrush current suppressor 80, thereby causing the relay switches withinthe inrush current suppressor 80 to be opened such that the AC powertransmission is disconnected and cut off from the output port 13. As aresult, the electronic equipment 90 (i.e., the load circuit) isprotected from overvoltage and/or undervoltage conditions.

While it is preferred that the control circuit utilize the relayswitches within the inrush current suppressor 80 to disconnect the ACpower transmission from the equipment 90, the invention is not solimited. For example, an additional switch (or set of switches) may beprovided anywhere along the transmission path to perform the disconnectfunction. While these switches can be provided anywhere in thetransmission path, it is preferred that they ale located downstream ofthe location where the under/overvoltage sensing circuit 40) monitorsthe voltage level of the AC power transmission.

The under/overvoltage sensing circuit 40 continues to monitor thevoltage level of the filtered AC power transmission even after thecontrol circuit has disconnected the AC power transmission from theequipment 90. Upon detecting that the voltage level of the filtered ACpower transmission returns to a safe operating level (i.e., between thepredetermined tipper and lower limits) the under/overvoltage sensingcircuit 40 generates and transmits the appropriate reconnect signal tothe control circuit 60. Upon receiving the reconnect signal, the controlcircuit 60 takes the appropriate action to reconnect the AC powertransmission to the output port 13. In the preferred embodiment, this isaccomplished by closing the appropriate relay switches within the inrushcurrent suppressor 80. In one preferred embodiment, the sensing circuit40 will have hysteresis of 7.5 volts to prevent repetitive disconnectionand reconnection of the AC power transmission to the output port 13.

All of the disconnect and reconnect functions are performedautomatically by the power conditioning system 100. The timing of anactions are also controlled by the control circuit 60. It should also benoted that while it is preferred that the voltage sensing circuit 40 bedesigned to detect and react to both overvoltage and undervoltageconditions in the AC power transmission, the invention is not solimited. In some embodiments of the invention, the voltage sensingcircuit 40 may only detect and react to overvoltage conditions. In otherembodiment, while less preferable, the voltage sensing circuit 40 mayonly detect and react to the undervoltage conditions.

The power supply 50 is used to power the control circuit 60.Specifically, the power supply 50 is coupled to the outlet leads of theEMI/RFI filter 30 so that it can convert the filtered AC powertransmission into low volt D.C. power. This low volt D.C. power is thensupplied to the control circuit 60.

The control circuit 60 is also operably coupled to a remote activationunit 30. The remote activation unit 30 enables the selectiveactivation/control of the inrush current suppressor 80 when neededand/or desired.

Finally, the order in which the components 20, 30, 40, 50, 60, 70 and 80are arranged within the power conditioning circuit is not limiting ofthe present invention. While the preferred order is illustrated for easeof description and understanding, those skilled in the art willappreciate that the components 20, 30, 40, 50, 60, 70 and 80 can bearranged in a wide variety of orders and sequences to achieve anequivalent system Many of the components 20, 30, 40, 50, 60, 70 and 80can be combined or further broken down on different circuit boards. Theinvention is not limited to any specific physical location of thecomponents 20, 30, 40, 50, 60, 70 and/or 80 on circuit boards. In otherembodiments of the present invention, one or more of the components 20,30, 40, 50, 60, 70 and/or 80 may be omitted. The internal elements andfunctions of each component of the power conditioning circuit will nowbe described below in detail with respect to FIGS. 2-6.

Referring now to FIG. 2, an exemplary EMI/RFI filter 20 for use in thepower conditioning system 100 is illustrated according to one embodimentof the present invention. The normal-mode and common-mode EMI/RFI filter30 receives an AC power transmission at the inputs 31, 131. A mutualinductor 32 functions so as to allow the normal 60 Hz AC powertransmission to pass therethrough with virtually no attenuation butpresents impedance to common-mode EMI and RFI, thus attenuating theseunwanted signals. The two ferrite beads 33, 34 are connected to themutual inductor 32 and serve two purposes. The first purpose of theferrite beads 33, 34 is to add series impedance to EMI and RFI, therebyfurther attenuating these signals. The second purpose of the ferritebeads 33, 34 is to prevent the filter circuit 30 itself from ringingwith mismatched input and output impedances, and to help control filtercharacteristics.

A first capacitor 36 and a first resistor 35 are connected in series tothe ferrite beads 33, 34 and provide a low impedance path fornormal-mode EMI and RFI, thereby attenuating these unwanted signals. Thefirst resistor 35 is a low value which is carefully chosen to controlthe Q of the filter circuit 30 and prevent it from ringing under impulseconditions. The first and second capacitors 37, 38 are connected inseries between the output terminals 139 and 39 and the chassis ground132. These capacitors 37, 38 provide a low impedance path to the chassisground 132 for common-mode EMI and RFI, thereby further attenuatingthese unwanted signals.

Referring now to FIG. 3, an exemplary power supply/converter circuit 50for use in the power conditioning system 100 is illustrated according toone embodiment of the present invention. The power supply circuit 50provides DC power to the sensing circuit 40, timing and control circuit60, remote activation unit 70, and the IP control circuit (illustratedin the embodiment of FIG. 7). The power supply circuit 50 is capable ofoperating with a wide range of AC voltages, but preferably with at least90 volts to 300 volts.

The power supply circuit 50 comprises a transformer 51 which isconnected to the input terminals 39, 139 which receive the AC powertransmission. The output of the transformer 51 provides a nominal 12volts AC to a bridge rectifier 52. The bridge rectifier 52 rectifies theAC to provide DC which is stored by a smoothing capacitor 53. Thenominal 12 volts DC on smoothing capacitor 53 powers all of thecircuitry of the power conditioning system 100 which requires 12 volts,including the five relays 49, 82, 83, 84 and 168. The power supplycircuit 50 also comprises a 7.5 volt Zener diode 55 that provides areference voltage for a regulator transistor 57. A resistor 56 suppliesthe reference diode 55 with a supply of current. The base of thetransistor 57 is connected to the junction of the resistor 56 and thezener diode 55 and is supplied with 7.5 volts. The emitter of transistor57 will be approximately 0.6 to 0.7 volts below the base and thereforesupply a steady nominal 7 volts DC to the circuitry that requires 7volts DC, including the timing and control circuitry 60, the remoteactivation unit 70, and the IP control circuitry (see FIG. 7). Acapacitor 58 is provided to decouple the output of the 7 volt powersupply. The resistors 151, 153 and 154 form a voltage divider to providea reference voltage at each of the two ports 155 and 156 for the timingand control circuit 60. A capacitor 152 provides decoupling andstability for the two reference voltages.

Referring now to FIG. 4, an exemplary under/over voltage sensing circuit40 for use in the power conditioning system 100 is illustrated accordingto one embodiment of the present invention. A bridge rectifier 41 isconnected to the 120 volt AC terminals 39 and 139. The bridge rectifier41 provides rectified AC which powers the sensing circuit 40. Thepurpose of the sensing circuit 40 is to measure the AC voltage beingsupplied through the power conditioning system 100 (and eventually tothe load 90) and to provide a signal at the output terminal 244 when theAC voltage is within a predetermined lower limit and a predeterminedupper limit as discussed in greater detail above with respect to FIG. 1.Whether the sensing circuit 40 sends the signal when the AC voltage ismeasured to be within the predetermined range, or when the AC voltage ismeasured to be outside the predetermined range, is of no consequence andboth aspects are considered to be within the scope of the presentinvention.

In one preferred embodiment, the sensing circuit 40 is designed toprovide the appropriate signal when the AC voltage is between 90 and 145volts RMS. In other words the upper limit is approximately 145 volts RMSand the lower limit is approximately 90 volts RMS. Of course theinvention is not so limited and any desired Lipper and lower voltagelimits can be used.

The sensing circuit 40 provides the necessary over/under voltage signal,in part, through the use of two zener diodes 46, 48 which are chosen tobreak down at 90 and 145 volts respectively. As mentioned above, thesevoltages are the preferred thresholds for the undervoltage shutdowncondition and the overvoltage shutdown condition respectively. Atransistor 45 in combination with the 7.5 volt zener diode 43, theresistor 42, and the resistor 44 form a constant-current source as doesa transistor 143 in combination with the 7.5 volt zener diode 245, theresistor 142, and the resistor 246. These two current sources functionto limit the current through each of the sensing zener diodes 46, 48,thereby preventing the sensing zener diodes 46, 48 from overheating whenthe AC voltage is excessive.

A relay 49 is controlled by the timing and control circuit 60 (FIG. 5)and has a 7.5 volt zener diode 47 connected to its contacts. The purposeof the relay 49 and the zener diode 47 is to provide hysteresis. Whenthe relay 49 is not energized, the zener diode 47 is connected in serieswith a sensing diode 46, thereby raising the undervoltage voltagethreshold by 7.5 volts. When the relay 49 is energized, the zener diode47 is in series with a sensing diode 48, thereby raising the overvoltagethreshold by 7.5 volts. Whenever the output terminal 244 is active, therelay 49 is energized by the timing and control circuit 60, therebyproviding hysteresis which prevents undervoltage or overvoltage shutdownfrom occurring inadvertently.

Two optical isolators (opto-isolators) 141, 144 are connected in serieswith the sensing zener diodes 46, 48. The two opto-isolators 141, 144provide safe isolation between the high-voltage AC and the low-voltageDC circuitry. When the AC voltage is above the undervoltage threshold,the zener diode 46 conducts, thereby allowing current to pass throughthe opto-isolator 141. This allows current to pass through the resistor243 and charge the capacitor 148. As the capacitor 148 charges, itpasses a current through the resistor 241 to charge the capacitor 242.This provides a delay of about one second before the signal at theoutput terminal 244 becomes active. Of course this timing is notlimiting of the invention and can be adjusted if needed. If the ACvoltage should drop below the undervoltage threshold there will nolonger be any current through the opto-isolator 141 and the voltageacross the capacitors 148, 242 will be discharged by the resistor 149.The time delay for these capacitors 148, 142 to discharge is long enoughto prevent the power conditioning circuit 100 from shutting off if theAC voltage only momentarily drops below the threshold due to an inrushcurrent condition when the load 90 (FIG. 1) is turned on.

When the AC voltage is above the overvoltage threshold the zener diode48 conducts, thereby allowing current to pass through the opto-isolator144. When the opto-isolator 144 turns on, the capacitor 242 isdischarged within 2 milliseconds, thereby deactivating the signal at theoutput terminal 244 faster than one half cycle of 60 Hz AC, which isapproximately 8.3 ms. Therefore, if there should be an overvoltagecondition, the output signal will shut off within the same half-cycle ofAC.

Referring now to FIG. 5, an exemplary timing and control circuit 60 foruse in the power conditioning system 100 is illustrated according to oneembodiment of the present invention. The purpose of the timing andcontrol circuit 60 is to control the relays 82, 83, 84 of the exemplaryinrush suppression/voltage disconnect relay circuit 80, and to controlthe hysteresis relay 49 of the sensing circuit 40 (FIG. 4). Thepreferred embodiment includes remote control, inrush current limiting,overvoltage shutdown and undervoltage shutdown functions in one controlcircuit in order to minimize cost and complexity. However, those skilledin the art will appreciate that other embodiments are possible whereeach function has a separate control circuit.

The circuitry of the timing and control circuit 60 is powered by the +7Vconnection 158 from the power supply 50. The functioning of the timingand control circuit 60 is based around four operational amplifiers 64,156, 160 and 161 (known commercially as Op-Amps) and four quadruple2-input AND gates 62, 63, 166 and 167. An octal darlington driver 262provides current to operate the relay coils and includes suppressiondiodes (not illustrated) to suppress back-EMF that may be generated whenthe relay coils are de-energized. The output of the sensing circuitenters at node 244, which is connected to the positive input of theOp-Amp 64 and the negative input is connected to the reference voltageat node 155. When the AC voltage is within the normal range, thepositive terminal 244 rises above the reference voltage supplied at node155, which is approximately 3.6 volts, the output of the Op-Amp 64 goespositive and enables the AND gates 63 and 166. Q2 of driver 262 is alsoactivated, thereby supplying current to the AC relay coil 86 (FIG. 6)and hysteresis relay coil 147 (FIG. 4) via the port 263. Thus, therelays 82, 49 are activated only when the AC voltage supplied to thepower conditioning circuit 100 is within the normal range.

The circuit 68 function as the power on/off circuit. When the powerswitch 67 is closed, the +7V from node 158 is applied to the AND gate63, which allows its output to go high. This in turn enables the ANDgate 62. The terminal 61 is the remote activation terminal froconnection to the remote activation unit 70 (FIG. 1) and can beenergized by a +5V logic signal. Other voltages can be used to energizethe circuit by using a simple potential divider made by using suitableresistors. It is also possible to energize the circuit by connecting aswitch from the terminal 61 to the +7V node 158 or by connecting a logicsignal from a separate circuit such as a TCP/IP (Internet Protocol) port(see FIG. 7). The output of the AND gate 62 will therefore be high onlywhen three conditions are met: (1) the AC voltage is within thepredetermined threshold/normal range; (2) the power switch 67 is on; and(3) the remote activation terminal 61 is high.

The output of the AND gate 62 is connected to the timing circuit whichconsists of the resistor 69, the capacitor 163, and the resistor 165.The resistors 69, 165 form a potential divider which provides an aimingvoltage of approximately 5.1 volts, and combined with the capacitor 163produces a time constant of approximately 0.5 second. The timing circuitis connected to the negative input of the Op-Amp 161 and the positiveinput of the Op-Amp 160. The positive input of the Op-Amp 161 isconnected to the voltage reference 155 which is approximately 3.6 volts,and the negative input of the Op-Amp 160 is connected to the voltagereference 156 which is approximately 3.0 volts.

When the output of the AND gate 62 is low, the voltage on the timingcircuit is close to zero, the output of the Op-Amp 161 is high, and theoutput of the Op-Amp 160 is low. When the output of the AND gate 62 goeshigh, the voltage of the timing circuit rises and the output of the ANDgate 167 goes high. This activates Q1 of the driver 262, therebysupplying current to the AC relay coil 181 via the port 265. Afterapproximately 0.5 second the voltage on the timing circuit reachesapproximately 3.0 volts and the output of the Op-Amp 160 goes high. Thiscauses the output of AND gate 166 to go high activating Q0 of driver 262and supplying current to AC relay coil 88 via port 264. Afterapproximately 0.1 second further the voltage on the timing circuitreaches approximately 3.6 volts and the output of Op-Amp 161 goes low,causing the output of the AND gate 167 to also go low. This de-activatesQ1 of the driver 262 which de-energizes the AC relay coil 181 via theport 265. The logic is designed so that if the sensing circuit output244 should go low at any time indicating that the AC voltage is out ofrange, all relay coils will be immediately de-energized.

The purpose of the relay 168 is to provide contacts for customer usewhich indicate that the AC output of the product is active. Thesecontacts can be used to communicate feedback to a piece of controlequipment or to connect to another identical piece of equipment for thepurpose of cascading units together. In this way, an unlimited number ofunits can be cascaded together. The Op-Amp 261 in combination with theresistor 169 and the capacitor 260 provide an additional 0.5 seconddelay so that the relay 168 has a total turn-off and turn-on delay ofapproximately 1.0 second. The Op-Amp 261 uses the reference voltage 156to provide a suitable on/off threshold and Q5 of the driver 262 suppliescurrent to the relay 168.

Referring now to FIG. 6, an exemplary inrush current suppressor/voltagedisconnect relay circuit 80 for use in the power conditioning system 100is illustrated according to one embodiment of the present invention. Theinrush current suppressor/voltage disconnect relay circuit 80 comprisesthree relays 82, 83, and 84. The three relays 82, 83, and 84 are chosento be capable of turning the AC power off and on to the load circuit 90(FIG. 1). Each relay 82-84 has one coil 86, 88, 181 and onenormally-open, single-pole contact 85, 87, 89. One side of each relaycoil 86, 88, 181 is connected to the +12 volt supply 157 and the otherside is controlled and energized by the timing and control circuit 60(FIG. 5).

The resistor 81 is a resistor that is chosen to be able to withstand120V AC for 0.5 second. The purpose of the resistor 81 is to limit theinrush current at the output 183 when it is activated. The output 182does not have inrush limiting and is designed to be active whenever theAC voltage is within the normal/operating range as determined by thesensing circuit 40. The coil 86 is energized through the port 263,thereby causing the contact 85 to close. The current supplied from theinput port 39 is therefore allowed to pass to the output port 182. Theoutput 183 is designed to be active only when three conditions are met:(1) the AC voltage is within the normal/operating range as determined bythe sensing circuit 40 (FIG. 4); (2) the power switch 65 (FIG. 5) is on;and (3) the remote activation input 61 is active (FIG. 5).

When all three conditions are met, a timing sequence initiated by thetiming and control circuit 60 controls the relays 83, 84 in a preciseway. Firstly, the relay coil 181 is energized through the port 265,thereby causing the contact 89 to close. This allows AC current to passfrom the input port 39, through resistor 81, and to the output port 183.After approximately 0.5 seconds, the relay coil 88 is also energizedthrough the port 264, thereby causing the contact 87 to close. Thecurrent supplied from the input port 39 is therefore allowed to passdirectly to the output port 183 bypassing the resistor 81. Afterapproximately a further 0.1 second, the relay coil 181 is de-energized,causing the contact 89 to open. The purpose of this is to prevent theresistor 81 from overheating should the contact 87 fail to close for anyreason. In this way, the AC current at the output port 183 is currentlimited for the first 0.5 seconds and then, after that time, the full ACcurrent potential is available.

Referring now to FIG. 7, a power conditioning system 100A is illustratedaccording to a second embodiment of the present invention. The powerconditioning system 100A is identical to that of the power conditioningsystem 100 of FIG. 1 with the exception that power conditioning system100A has internet protocol (“IP”) control capabilities. A detaileddiscussion of those components of the power conditioning system 100Athat are substantially identical to that of the power conditioningsystem 100 is omitted in order to avoid redundancy. However, forreference, like numbers are used to identify like parts with theexception of the alphabetical suffix “A” being added.

The power conditioning system 100A comprises an Ethernet port 110 forconnecting the power conditioning system 100A to a network 111A, such asthe internet. Other suitable networks can include local area networks,wide area networks, or intranets. The Ethernet port 110A is operablycoupled to the control circuit 60A and preferably resides within thehousing of the power conditioning system 100A. The internal circuitry ofthe control circuit 60 is coupled to the Ethernet port 60A in a mannerwell known in the art. An ethernet cable or other communication line canbe used couple the Ethernet port 110A to the network 111A.Alternatively, a wireless connection can be established. Moreover, whilean Ethernet port is illustrated as providing the means to couple thepower conditioning system 100A to the network, other hardware can beused, such as a phone jack, a firwire port, etc.

The control circuit 60A, or other component of the power conditioningsystem 100A, is programmed with the proper software to facilitatecommunication, monitoring, and control of the power conditioning system100A via the network 111A from a remote location. As can be seen fromthe arrows in FIG. 1 the control circuit 60A both receives and transmitsdata to the network 111A via the Ethernet port 110A. this allows a userto monitor and control the power conditioning system 100A from a networkportal/interface, such as an internet site or the like.

While the invention has been described and illustrated in detail,various alternatives and modifications will become readily apparent tothose skilled in the art without departing from the spirit and scope ofthe invention. Specifically, the invention can take on a wide variety ofembodiments that omit one or more of the components illustrated in FIGS.1 and 7. For example in some embodiments, the invention can be a systemfor conditioning an AC power transmission that comprises only thevoltage surge protector, the inrush current suppressor, and the networkconnection means. In a further example, the invention call be a systemcomprising only the voltage surge protector, the voltage sensingcircuit, and the network connection means.

1. A system for conditioning an alternating current (“AC”) powertransmission for supply to a load circuit, the system comprising: apower conditioning circuit comprising a voltage surge protector foreliminating voltage spikes in the AC power transmission, an inrushcurrent suppressor for limiting the current of the AC powertransmission, a filter for reducing electromagnetic interference andradio frequency interference of the AC power transmission, and a voltagesensing circuit for monitoring a voltage level of the AC powertransmission; means for electrically coupling the power conditioningcircuit to a source of AC power; outlet means for electrically couplingthe power conditioning circuit to a load circuit; wherein the voltagesensing circuit monitors the AC power transmission in a rectifiedun-smoothed state after the AC power transmission has passed through thefilter; and wherein upon the voltage sensing circuit detecting that thevoltage level of the AC power transmission exceeds a predetermined upperlimit, the AC power transmission is prohibited from reaching the outletmeans.
 2. The system of claim 1 further: wherein the voltage surgeprotector is coupled directly to the means for electrically coupling thepower conditioning circuit to a source of AC power, thereby producing asurge protected AC power transmission; wherein the filter is coupled tothe voltage surge protector and receives the surge protected AC powertransmission, thereby creating a surge protected and filtered AC powertransmission; and wherein the voltage sensing circuit monitors the surgeprotected and filtered AC power transmission.
 3. The system of claim 1wherein the power conditioning circuit further comprises: one or moreswitches and a controller, the controller operably coupled to thevoltage sensing circuit and the one or more switches, the voltagesensing circuit adapted to generate and transmit an overvoltage signalto the controller when the voltage level of the AC power transmissionexceeds the predetermined upper limit; and wherein upon receiving theovervoltage signal from the voltage sensing circuit, the controllertransmits a disconnect signal to the one or more switches, therebyprohibiting the AC power transmission from reaching the outlet means. 4.The system of claim 3 wherein the one or more switches are relayswitches in the inrush current suppressor.
 5. The system of claim 1wherein the voltage sensing circuit is further adapted so that upondetecting that the voltage level of the AC power transmission dropsbelow a predetermined lower limit, the AC power transmission isprohibited from reaching the outlet means.
 6. The system of claim 5further comprising: wherein upon the voltage level of the AC powertransmission being detected to be above the predetermined upper limit,the AC power transmission is prohibited from reaching the outlet meanswithin at least one half cycle of the AC power transmission; and whereinupon the voltage level of the AC power transmission being detected todrop below the predetermined lower limit, the prohibition of the ACpower transmission from reaching the outlet means is delayed for aperiod of time to prevent the AC power transmission from beingprohibited from reaching the outlet means during momentary drops in theAC power transmission below the predetermined lower limit.
 7. The systemof claim 6 wherein the period of time is about 1 second.
 8. The systemof claim 1 further comprising: one or more switches, a controlleroperably coupled to the voltage sensing circuit and the one or moreswitches, the voltage sensing circuit adapted to (1) generate andtransmit an overvoltage signal to the controller when the voltage levelof the AC power transmission exceeds the predetermined upper limit and(2) generate and transmit an undervoltage signal to the controller whenthe voltage level of the AC power transmission drops below apredetermined lower limit; wherein upon receiving the overvoltage signalfrom the voltage sensing circuit, the controller transmits a disconnectsignal to the one or more switches, thereby prohibiting the AC powertransmission from reaching the outlet means within at least one halfcycle of the AC power transmission from when the voltage sensing circuitdetected that the AC power transmission exceeded the predetermined upperlimit; and wherein upon receiving the undervoltage signal from thevoltage sensing circuit, the controller transmits a disconnect signal tothe one or more switches only after a delay period, thereby prohibitingthe AC power transmission from reaching the outlet means.
 9. A systemfor conditioning an alternating current (“AC”) power transmission forsupply to a load circuit, the system comprising: a power conditioningcircuit comprising a voltage surge protector for eliminating voltagespikes in the AC power transmission, an inrush current suppressor forlimiting the current of the AC power transmission, and a voltage sensingcircuit for monitoring a voltage level of the AC power transmission;means for electrically coupling the power conditioning circuit to asource of AC power; outlet means for electrically coupling the powerconditioning circuit to a load circuit; wherein upon the voltage sensingcircuit detecting that the voltage level of the AC power transmissionexceeds a predetermined upper limit, the AC power transmission isprohibited from reaching the outlet means within at least one half cycleof the AC power transmission; and wherein upon the voltage sensingcircuit detecting that the voltage level of the AC power transmissiondrops below a predetermined lower limit, the AC power transmission isprohibited from reaching the outlet means only after a delay period hasexpired and the voltage level of the AC power transmission is stillbelow the predetermined lower limit.
 10. The system of claim 9 whereinthe delay period is selected so as to prevent the AC power transmissionfrom being prohibited from reaching the outlet means during momentarydrops below the predetermined lower limit.
 11. The system of claim 10wherein the delay period is about one second.
 12. The system of claim 9wherein the power conditioning circuit further comprises a filter forreducing electromagnetic interference and radio frequency interferenceof the AC power transmission; and wherein the voltage sensing circuitmonitors the AC power transmission in a rectified un-smoothed stateafter the AC power transmission has passed through the filter.
 13. Thesystem of claim 9 further comprising means for coupling the powerconditioning circuit to a network thereby facilitating monitoring and/orcontrol of the power conditioning circuit from a remote location via anetwork portal.
 14. The system of claim 9 further comprising a housing,the power conditioning circuit located within the housing, wherein theoutlet means comprises a plurality of AC outlets, and the means forelectrically coupling the power conditioning circuit to a source of ACpower comprises a plug.
 15. A system for conditioning an alternatingcurrent (“AC”) power transmission for supply to a load circuit, thesystem comprising: a power conditioning circuit comprising a voltagesurge protector for eliminating voltage spikes in the AC powertransmission, an inrush current suppressor for limiting the current ofthe AC power transmission, a voltage sensing circuit for monitoring avoltage level of the AC power transmission, the inrush currentsuppressor having one or more relay switches, and a controller operablycoupled to the voltage sensing circuit and the one or more relayswitches; means for electrically coupling the power conditioning circuitto a source of AC power; outlet means for electrically coupling thepower conditioning circuit to a load circuit; the voltage sensingcircuit generating and transmitting an overvoltage signal to thecontroller when the voltage level of the AC power transmission exceeds apredetermined upper limit; wherein upon receiving the overvoltage signalfrom the voltage sensing circuit, the controller transmits a disconnectsignal to the one or more relay switches of the inrush currentsuppressor, thereby prohibiting the AC power transmission from reachingthe outlet means and wherein during an inrush current condition, the oneor more switches limit the current of the AC power transmission thatreaches the outlet means without disconnecting the AC power transmissionfrom reaching the outlet means.
 16. The system of claim 15 wherein thepower conditioning circuit further comprises a filter for reducingelectromagnetic interference and radio frequency interference of the ACpower transmission; and wherein the voltage sensing circuit monitors theAC power transmission in a rectified un-smoothed state after the ACpower transmission has passed through the filter.
 17. The system ofclaim 15 further comprising: the controller further adapted to generateand transmit an undervoltage signal to the controller when the voltagelevel of the AC power transmission drops below a predetermined lowerlimit; wherein upon receiving the overvoltage signal from the voltagesensing circuit, the controller transmits the disconnect signal to theone or more switches, thereby prohibiting the AC power transmission fromreaching the outlet means within at least one half cycle of the AC powertransmission from when the voltage sensing circuit detected that the ACpower transmission exceeded the predetermined upper limit; and whereinupon receiving the undervoltage signal from the voltage sensing circuit,the controller transmits a disconnect signal to the one or more switchesonly after a delay period, thereby prohibiting the AC power transmissionfrom reaching the outlet means.
 18. The system of claim 17 wherein thedelay period is selected so as to prevent the AC power transmission frombeing prohibited from reaching the outlet means during momentary dropsbelow the predetermined lower limit.
 19. The system of claim 18 whereinthe delay period is about one second.
 20. The system of claim 15 furthercomprising means for coupling the power conditioning circuit to anetwork thereby facilitating monitoring and/or control of the powerconditioning circuit from a remote location via a network portal.